Food, Mood, and Cognition

What are nutraceuticals?

Foods containing bioactive compounds with health-promoting, disease-preventing, or medicinal properties.

Why is serotonin described as nutrient-dependent?

It depends on tryptophan (TRP), an essential amino acid.

Does eating more protein increase happiness?

No. High-protein diets reduced serotonin in rats due to amino acid competition.

What did Young (1986) find about tryptophan?

TRP administration can reduce depressive symptoms.

What did Kikuchi et al. (2021) conclude about TRP supplements?

TRP supplementation can improve mood in healthy volunteers.

What is the Wurtman Hypothesis?

Insulin release after carbohydrate intake reduces competing long-chain amino acids, allowing more tryptophan to enter the brain and increase serotonin.

Which conditions are associated with carbohydrate cravings?

Depression, pre-menstrual syndrome, and seasonal affective disorder.

What did Mantantzis et al. (2019) find?

A systematic review found no evidence that carbohydrates improve mood.

How does hypoglycaemia affect people with T1D vs T2D?

T1D individuals show reduced frontal lobe blood flow during hypoglycaemia; T2D do not (reason unclear).

What did Owen et al. (2010) find?

Glucose drinks enhanced word recognition and implicit memory in a double-blind study.

What did Stollery & Christian (2016) show about task difficulty?

The cognitive benefit of glucose depends on how demanding the task is.

What did Molden et al. (2012) find about glucose mouth rinse?

It can produce minor cognitive enhancement without ingestion.

What did Miller et al. (2012) find about fructose?

Fructose may also enhance cognition.

Caffeine & Cognition

effects may reflect a withdrawal reversal rather than actual enhancement. caffeine in non-consumers can impair performance and in people who are not deprived have no additional benefit

Why is tea associated with relaxation despite caffeine content?

Tea contains L-theanine.

What does L-theanine do in the brain?

Enhances alpha-wave activity linked to relaxation (Kelly et al., 2008).

What cognitive effects does L-theanine have?

Improves attention (Baba et al., 2021).

What did Fontani et al (2005) find?

omega-3 improved mood in healthy individuals.

What did Emery et al. (2020) conclude?

Meta-analysis found omega 3 provides no cognitive benefit in healthy groups.

Why is evidence for the Mediterranean diet mixed?

Many confounding variables (exercise, lifestyle, climate).

What are flavonoids?

Compounds giving colour to foods such as chocolate and red wine.

What did Williams et al. (2008) find about blueberries?

Supplementation enhanced memory in rats, especially aged rats.

What did Krikorian et al. (2010) show?

Long-term blueberry supplementation slowed memory loss in older adults.

What did Whyte & Williams (2015) find in children?

A single dose of blueberry extract improved memory and mood in 8–10-year-olds.

How is body size related to memory?

Higher body size is negatively associated with memory performance (Cheke et al., 2016).

What is the Vicious Cycle Model?

Obesity and cognitive decline reinforce each other through behavioural and neural mechanisms.